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Fixe PLX HCR - "New"? Metal as alt to Titanium?
Brian in SLC wrote: Uri Geller...funny...I got that reference...! The Malta bolt is the one from over 4 years ago? climbmalta.com/news/warning… When you say its happening increasingly often...its that true on Malta? They've been fighting "bad nuts" for awhile, but, no more bolt failures reported? They seem to have a gob of routes in the "splash zone". Sounds like their bolting policy has gone to recommending titanium for these splash zone routes. Darn place is on my list to visit...I'm not sure whether this was the actual bolt in question Brian. I'm told that there have been several stainless bolt failures on Malta and its smaller sister island Gozo. The Climb Malta link speaks of high humidity being an important factor in promoting SCC but that is not my experience. The highest corrosion rates are at a moderate humidity level. Higher and lower humidity reduce corrosion rates - put 316 in seawater and it will last longer than if you place it 20 metres away from the sea. Maybe this is why 316 lasts a long time on boats that are rinsed regularly. Bolts in the splash zone are not necessarily worse than ones further up in my experience. I had a great time on Malta and Gozo just over a year ago - Great climbing in often spectacular situations. Fairly soft limestone often with the texture of sandstone on the seacliffs - highly recommended, go for it! |
Martin Roberts wrote: The Climb Malta link speaks of high humidity being an important factor in promoting SCC but that is not my experience. The highest corrosion rates are at a moderate humidity level. Higher and lower humidity reduce corrosion rates - put 316 in seawater and it will last longer than if you place it 20 metres away from the sea. Maybe this is why 316 lasts a long time on boats that are rinsed regularly. Bolts in the splash zone are not necessarily worse than ones further up in my experience.Yes, my experience as well. Further, both A. Sjong's and T. Prosek's published works, plus several newer formal analyses, show that moderate humidity, 30 - 50% RH, promotes SCC better than high humidity. And yes, this is why 316 "Marine Grade" is appropriate for boats. As long as the metal is regularly rinsed, either by salt or fresh water, SCC generally doesn't start and the continuously high humidity helps as well. |
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Xavier Legendre wrote:Hello If"moderate humidity rate 30-50% rh promotes faster SCC corrosion",why were the first cases of Stainless bolt failures happening in Phra Nang(Thailand) where humidity rates are much higher(60 to 80% rh or even more) SCC corrosion is happening around the Mediterranean sea but at a much slower rate than tropical regions... Lower humidity rates?Good questions Xavier. It can be higher than 90%rh in Thailand but it is pretty low at other times. And yes, rh will be lower in the Mediterranean area. SCC failures are slower in the Med but they are still happening in around 10 years installed, sometimes more, sometimes less. What I found on this trip to Thailand was that under the crust of corrosion there is pH 1 to pH 2! On top of this exact same corrosion crust the pH was 8, just like all other bolt and rock surfaces around, whether corroded or not. How small is a 'micro-environment'? Well this particular one was about only 25 square mm (a bit less than 1/4" x 1/4"). Once this scab has formed there is probably little to no effect from the environment around. It seems that southern Thailand, Cayman Brac, Taiwan, central and south America and an increasing number of places are able to initiate SCC quicker than others. The reasons are still a bit of a mystery. There are many factors at play other than relative humidity |
Martin Roberts wrote: What I found on this trip to Thailand was that under the crust of corrosion there is pH 1 to pH 2! On top of this exact same corrosion crust the pH was 8, just like all other bolt and rock surfaces around, whether corroded or not. How small is a 'micro-environment'? Well this particular one was about only 25 square mm (a bit less than 1/4" x 1/4"). Once this scab has formed there is probably little to no effect from the environment around.WOW! That's astounding! That's quite outside the range I'd expect if it were from (weak) carbonic acid from rotting plants. Any ideas on why? |
John Byrnes wrote: WOW! That's astounding! That's quite outside the range I'd expect if it were from (weak) carbonic acid from rotting plants. Any ideas on why?Angele Sjong suggested that there would be very low pH causing problems as I remember. We know a man who should be wishing his hat is tasty (email me if you don't know who). Only interesting theories at the moment John but I'll certainly let you know as I find out more. We are being careful not to suggest something that could be wrong or misleading. I'm not a chemist, I'm the dogsbody doing the graft, working under the direction of Alan Jarvis and David Reeve. I'm packaging some samples to send to Dave in Australia right now as it happens. This is officially a UIAA project so I'm not supposed to reveal much before they do. |
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So! Back to the topic of this thread regarding duplex being a replacement for Titanium. |
Martin Roberts wrote:So! Back to the topic of this thread regarding duplex being a replacement for Titanium. This photo is 18 months old now so I feel I can show it. It's what happens to duplex 2205 after 18 months in the 'Long Term Thailand Corrosion Test'. Cluster 38 is about 5m horizontally from high tide. This is one of the most corroded of the 2205 bolts... For comparison sake, below are other bolts in the same cluster, first is a 304 Expansion bolt in the same cluster... Here is another 304 Expansion bolt... Here is a 316 Expansion bolt... Here is a 1.4529 nut, bolt and washer with a 254SMO hanger (all 6 Moly - what I would call 'HCR'). Most bolts of this material don't have any more corrosion that his one... Here is the Grade 2 Titanium bolt in the same cluster (the duplex bolt is in the background). No Titanium bolt shows any corrosion at all in any of the 45 clusters... Again, I must stress that this corrosion test is a UIAA project, I am the installation and inspection guy. This is not a comparison of manufacturers or the equipment they produce. It is purely scientific to compare how a large range of factors alter the speed of corrosion and failure of different materials of different designs. Some are expected to fail. There will be no mention of manufacturers, although some will be obvious from photos released of course. Bolts have either been given free of charge or bought at cost price.Who makes the 254SMO hanger? I was not aware those existed. Outside of Fixe's new HCR whatever and Petzl's 904L hanger, I was not aware anyone made HCR hangers. |
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20 kN wrote: Who makes the 254SMO hanger? I was not aware those existed. Outside of Fixe's new HCR whatever and Petzl's 904L hanger, I was not aware anyone made HCR hangers.The 254SMO hanger was made by us (Titan Climbing) just for this "Long Term Corrosion Test". 254SMO is a trade name for what is pretty much exactly the same as 1.4529 - a REAL HCR in my opinion. We had the hangers laser cut and laser marked in 254SMO (marked 'HCR'), 304 and 316 for direct comparison. What does anybody think about when comparing the photos of the 'HCR' hanger and the Fixe PLX 'HCR'? In my opinion they are a world apart and it seems unfair to me to use the same 'HCR' term for both materials (as well as 904L). We bought an extremely expensive sheet of 254SMO and I would be very happy to make up some nicer hangers than the prototypes pictured above if anybody needs any by the way |
Xavier Legendre wrote:Hello Very interesting pictures,Martin, What would be interesting is to pull test those bolts to see what is left of their strength after this period. But I am pretty sure this is the next step in your tests. The hanger "20kn" is talking about sure looks like a Fixe 2 HCR hanger,but without the ring,probably a prototype since Fixe HCR hangers are just coming out on the market...I have given them all a simple pull test of about 3kN to 4kN. None have failed yet, even the 304. Are you talking about the hanger with the yellow UIAA tag? That's one of ours - Titan Climbing |
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Martin Roberts wrote: The 254SMO hanger was made by us (Titan Climbing) just for this "Long Term Corrosion Test". 254SMO is a trade name for what is pretty much exactly the same as 1.4529 - a REAL HCR in my opinion. We had the hangers laser cut and laser marked in 254SMO (marked 'HCR'), 304 and 316 for direct comparison. What does anybody think about when comparing the photos of the 'HCR' hanger and the Fixe PLX 'HCR'? In my opinion they are a world apart and it seems unfair to me to use the same 'HCR' term for both materials (as well as 904L). We bought an extremely expensive sheet of 254SMO and I would be very happy to make up some nicer hangers than the prototypes pictured above if anybody needs any by the wayWhat about the bolt? I've never seen anyone make a 254SMO expansion bolt either. Seems interesting, but probably of little practice application as nearly all highend HCR metals are more expensive than titanium leaving no remaining benifit. |
Martin Roberts wrote: I have given them all a simple pull test of about 3kN to 4kN. None have failed yet, even the 304. Are you talking about the hanger with the yellow UIAA tag? That's one of ours - Titan ClimbingWow, thats amazing. I expected a lot worse from the picture of the 304 bolt. Perhaps next time testing to 5kn might be better as that is the standard for protection pieces, IIRC |
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So how the hell is the run of the mill, dirt-bag route setter going to pay for these bolts, hangers, and chains? A ten bolt line with a two bolt chain anchor would be what...$160.00? Development is going to slow down. I need to find more cracks! |
John Byrnes wrote:Martin, Excellent information and documentation. Thanks so much. I'm going to send that pH info to Angele and see what she thinks. I'm totally curious! And I'll eat my hat if those two 304 bolts last 30 months! ;-)It´s ion exchange, a well known effect in corrosion sites really..... |
Martin Roberts wrote:This photo is 18 months old now so I feel I can show it.Martin- Can you comment on the location of the bolts with respect to exposure to sun and exposure to rainfall run-off? You mention they are all roughly 5m above high tide level. From the original paper studying the SCC failure of the Thailand SS bolts ( researchgate.net/publicatio…) it suggests that the failures were due to lower relative humidity and exposure to MgCl and ZnCl salts. This situation could potentially be significantly worse higher up (than at 5m above high tide) on cliffs with greater exposure to rainwater run-off and more direct sun. Very great work and looking forward to more information as it becomes available! -Slavens |
John Byrnes wrote:Martin, Excellent information and documentation. Thanks so much. I'm going to send that pH info to Angele and see what she thinks. I'm totally curious! And I'll eat my hat if those two 304 bolts last 30 months! ;-)Thanks and you're welcome John. Please copy me in to the email to Angele. You're going to have to eat your hat though because they were still on the wall after the 36 month inspection. I've not had time to document the photos yet from this most recent 36 month inspection. 20 kN wrote: What about the bolt? I've never seen anyone make a 254SMO expansion bolt either. Seems interesting, but probably of little practice application as nearly all highend HCR metals are more expensive than titanium leaving no remaining benifit.The bolt was mentioned in the photo description above. It's 1.4529 (almost the same composition as 254SMO), as well as the washer and nut. Several companies make them but they are about 3 to 5 times more expensive to buy than a 316 equivalent from the same company. We used 254SMO just because it is available in sheet form whereas 1.4529 is more common in bar form. Mike Slavens wrote: Martin- Can you comment on the location of the bolts with respect to exposure to sun and exposure to rainfall run-off? . Very great work and looking forward to more information as it becomes available! -SlavensHi Mike. Sure, installation notes on this particular cluster: "Klong Ying Seua. South end of Nopparat Thara Beach. Approx 30 metres further round coast from Cluster 37. Top one of the three clusters close together. North 08degrees 02.234' East 098degrees 48.867' Very hard grey rock with white veins and grey/brown surface. 4 metres horizontally from high tide and 3 metres above high tide. Very dry drill dust. 15 degrees overhanging. Vegetation on top of cliff. No direct rain fall but possible to blow in during a storm. Likely to get rainwater run off in heavy rain. Only late afternoon sun exposure." When I visited this cluster at the 18 month inspection it was at the end of the rainy season in August 2015. There was some seepage as can be seen in the photos above. I can't stress enough that there are many environmental factors at play so anything is possible. I saw what looks like a mild steel bolt with a stainless hanger just 4 or 5 metres above the sea which is possibly 20 years old that is close to these test clusters. No sign of SCC - I removed it for analysis by applying about 40Nm torque to the nut and the stud sheared. It had pH11 to pH14 on the rust from the steel! I'm expecting the rust on the stainless hanger to have pH1 to pH2 under the rust crust just like all other stainless bolts just a couple of metres away - then we have the polar opposite pH readings just 3 mm apart! In other places we have bolts much further from the sea that have failed from SCC in a couple of years. Somewhere between 200 and 300 bolts have failed in the area to what is most likely SCC. The variables are enormous. Both stainless anchor bolts failed simultaneously under bodyweight at a belay station in Thailand just 6 weeks ago - Nobody hurt thankfully as a Titanium bolt was clipped off to the side apparently. Photos of possibly ancient mild steel bolt with stainless hanger mentioned above...    |
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^^^Wow...that's a wild looking mild steel bolt! I'd think between the usual concerns for a galvanic cell situation, and, the harsh environment, a carbon steel bolt wouldn't last that long. Things that make you go "hmmm"... |
Martin Roberts wrote: Thanks and you're welcome John. Please copy me in to the email to Angele. You're going to have to eat your hat though because they were still on the wall after the 36 month inspection.I'll copy you on the email. I may be munching on my chapeau eventually, but I meant staying on the wall during a pull-test. I've seen total-crap bolts stay on the wall for 18 years if they're not stressed, but you can break them off with your fingers. |
